Sant'Ambrogio e Carlo al Corso is a basilica church in Rome, facing onto the central part of the Via del Corso. The apse of the church faces across the street, the Mausoleum of Augustus on Via di Ripetta. This church is dedicated to Saint Ambrose and Saint Charles Borromeo, both natives of Milan. It is one of at least three churches in Rome dedicated to Borromeo, others including San Carlo ai Catinari and San Carlo alle Quattro Fontane. Its construction was begun in honour of the canonization of St. Charles Borromeo in 1610, under the direction of Onorio Longhi and, after his death, of his son Martino Longhi the Younger. The site was that of the former church of San Nicola de Tofo.